Q:How can i Combine a fluid simulation with an ocean plane?
Here is a complete tutorial on how to combine ocean modifier and fluid sim to generate exactly what you are looking for: https://www.youtube.com/watch?v=qVwfEHtLiyI

And here is a simpler version just with the Ocean Modifier (for zoomed out shots for example): https://www.youtube.com/watch?v=smArCTzxGpE

Both techniques can be combined but tend to be resource-intensive when rendering. I would move between two scenes (close and wide) to optimize.